Internal combustion engines with reciprocating pistons that move within cylinders and thus form combustion chambers are sufficiently well known from prior art. In recent years numerous devices and methods have been suggested for improving the combustion of the mixture introduced into the combustion chamber in order to improve control of the combustion process and enable a more environmentally friendly combustion of the mixture. A known method is to measure the pressure in the cylinder. By referring to the changes over time in the volume of the combustion chamber, which can be determined from the geometrical relationships between the internal combustion engine and the crank shaft angle of rotation, it is possible to determine among other things the energy being released during a combustion process, in order to improve combustion by taking this variable and others into account.
When determining the parameters of the combustion process, the conventional wisdom is to proceed from the assumption that a mixture in the combustion chamber begins to react chemically, that is, to burn, after certain physical and environmental conditions such as pressure and temperature have occurred or following ignition by a spark plug. Proceeding from the start of combustion estimated on this basis, a conclusion about the further progress of the combustion is reached by reference to further determined variables. The problem with this method is that if an incorrect assumption is made about the start of combustion, further calculations are likewise prone to error.